Priming method for filter

ABSTRACT

A priming method for a filter, whereby the outlet of a spent filter is connected to the inlet of a fresh filter, and the spent filter is inverted. A drain in the spent filter is then opened to allow air to enter the spent filter and fluid to drain from the clean side of the spent filter into the fresh filter.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of the filing date of U.S.Provisional Patent Application Ser. No. 61/181,436, filed May 27, 2009,the disclosure of which is incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

The present invention relates generally to fluid filters, and to amethod for priming such filters.

BACKGROUND OF THE INVENTION

Certain fluid filters are supported on a bracket (or other supportdevice), and have a quick-release feature to allow the filter to bequickly and easily removed from such bracket. In a vehicle for example,it can be desirable to have a bracket on an engine, in the enginecompartment, or other appropriate support location on the vehicle, andto have quick attachment means for mounting the filter to the bracket,and for removing the filter when it is desirable, for example, to accessthe filter remotely for repair, or for replacement of a spent element.

The type of attachment (or connection) for such application should berobust and secure, and prevent inadvertent detachment of the filter fromthe bracket during use. Nevertheless, it should be relatively easy toattach and detach the filter from the bracket when desired. And ofcourse, in general, the connection should also be relativelylightweight, compact, easy to assemble, and cost-effective tomanufacture.

It is known to provide a T-slot on the back side of a filter that slidesinto a slot in a bracket. The filter is basically just slid axiallydownwards onto the slot for attachment, and slid axially upwards off thebracket for detachment. This can be appropriate when there is sufficientaxial space to accomplish this movement, and when the hoses are eitherlong enough or in an appropriate location to allow for this, or can bedetached from the element prior to such axial movement. It is also knownto provide a bracket with slots and openings, and a mounting piece onthe back of the filter that includes posts and a spring clip, and whichengages the slots and openings when the filter is slid axially onto thebracket. Once the filter is installed, the spring clip engages thebracket and retains the filter on the bracket until the clip isdepressed and the filter can then be axially slid off the bracket. Thistechnique also requires sufficient axial space, requires access to thespring clip on the back of the filter, and has the same issues asdescribed above with respect to the hoses.

U.S. patent application Ser. No. 12/472,668, for “Filter With QuickAttachment Features”, filed May 27, 2009, addresses at least some of theissues associated with such prior art, and provides a filter and aconnection for such filter to a bracket or other support device, whichdoes not require the full axial movement of the filter with respect tothe bracket for attachment and detachment; but rather allows the filterto be removed primarily by pivoting the element away from the bracket.Such a connection and technique requires less free space above thefilter, does not require access to the rear of the filter, and is lessdisruptive of any attached hoses and other components.

After such a filter is removed from a bracket or other support, and anew filter with a fresh element is to be mounted to the bracket, it is acommon issue that the new filter needs to be primed before it is used.That is, the new filter is filled with air, and it is desirable toremove (bleed) the air from the filter before use as the air pocket mayblock some of the media from being used for filtration and can otherwisecause issues within the fluid system (e.g., it can be more difficult tostart an engine). Various techniques have been used to prime filters,including using a bleed valve and priming pump to force fluid into themedia, as in Clausen U.S. Pat. No. 5,643,446. While some techniques haveproved successful in the marketplace, it is believed there is a demandin the industry for yet a further technique—and particularly for atechnique that is simple and straightforward, and results in most if notall air being removed from an element prior to its use without requiringpumps or specialized valves.

SUMMARY OF THE INVENTION

The present invention provides a method for priming a filter which issimple and straightforward, and results in most if not all air beingremoved from the filter prior to its use. Such a technique does notrequire additional pumps or specialized valves.

According to the present invention, the filter includes a ring offiltration media enclosed within a canister, and an end cap is fixed tothe open upper end of the canister. Inlet and outlet ports are providedin the end cap to direct fluid into and out of the canister. The filterfurther includes attachment structure to enable the filter to beattached to a bracket or other support surface. The attachment structureincludes a pair of radially-outward projecting pivots located onopposite sides of the canister toward a lower end thereof. The pivotseach comprise a base and an enlarged head, with the head including anunderside tapered surface defining a lip. The base defines a stand-off,with the stand-offs being dimensioned to be closely received within thesidewalls of the bracket.

The attachment structure further includes a pair of retaining clips alsolocated on opposite side of the canister, but toward the upper endthereof. Each clip is in substantial axial alignment along the side ofthe housing with a respective pivot, and has a radially flexible axialbody portion, and an integral tab portion at the free end of theretaining clip. An outwardly-projecting stand-off is also providedadjacent the tab end of the retaining clip, with the stand-offs of theclips being dimensioned to be closely received within the arms of thebracket, and preventing the tab ends of the clips from being pressedagainst the sides of the canister; or in other words, allowing some freespace between the tab ends of the clips and the canister such that thetabs can be pressed inwardly when it is desired to remove the filterfrom the bracket, as will be more fully described herein.

The bracket for the filter includes a body and a pair of side walls,with the sidewalls projecting outwardly from the body in spaced-apartrelation such that the filter can be closely received therebetween. Eachof the sidewalls includes i) a hook-shaped slot dimensioned to receive arespective pivot on the filter, and allow the filter to pivot from anorientation at an angle to the longitudinal axis of the bracket, to anorientation where the filter is substantially axially-aligned with andsupported against the bracket; and ii) a catch dimensioned to engage andretain a respective retaining clip, when the filter is aligned with thebracket. The inner tapered lip surface on the head of each pivotfacilitates locating the pivots within the hook-shaped slots, and hencefacilitates locating the filter on the bracket. The stand-offs on thebase of the pivots help orient the filter with the bracket, and ensure asecure and robust connection.

The tab on each clip can include a radial projection which is receivedin a small slot or hole in the bracket, to lock the filter to thebracket. Pressing the tabs inwardly toward the canister releases theprojections from their respective slots, and enables the upper end ofthe filter to be pivoted away from the bracket. The filter can then belifted slightly upwardly and outwardly away from the bracket such thatthe pivots are removed from their respective hook-shaped slots and thefilter can be inspected, repaired and/or replaced.

When the filter is to be replaced with a filter having a fresh element,a cap is located over the inlet to the spent filter, and the outlet ofthe spent filter is connected to the inlet of the fresh filter via ashort connector tube. The spent filter is then inverted, the drain forthe spent filter is opened, and the fluid in the spent filter is allowedto drain under gravity into the fresh filter until the fluid fills thefresh filter and all the air is expelled through the outlet port of thefresh filter. As the fluid passing into the fresh filter is from the“clean” side of the spent filter, the fresh filter will not becomeloaded with particulate matter before use. The spent filter can then bedisconnected from the fresh filter, and disposed of as appropriate. Asan additional benefit, the spent filter is essentially devoid of fluid,which facilitates disposal of the filter in a landfill or other wastedisposal facility. The fresh filter can then be connected to the hoseswithin the system and mounted such as to the support bracket describedabove.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevated perspective view of a filter assembly according tothe present invention;

FIG. 2 is an elevated perspective view of the filter for the assembly ofFIG. 1;

FIG. 3 is a cross-sectional side view of the filter of FIG. 2;

FIG. 4 is an enlarged view of a portion of the filter shown in FIG. 2;

FIG. 5 is an elevated perspective view of a bracket for the assembly ofFIG. 1;

FIG. 6 is an elevated perspective view of the filter assembly of FIG. 1,showing the filter partially assembled with the bracket; and

FIG. 7 is an elevated perspective view of a spent filter connected to afresh filter showing the priming method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, and initially to FIG. 1, a filter assemblyaccording to the present invention is indicated generally at 10. Filterassembly 10 includes a filter 12 and a support bracket 14 with sidewalls16. Filter 12 and bracket 14 have a quick attachment feature as will bedescribed below.

Referring now to FIGS. 2-4, filter 12 includes an outer cup-shapedcanister or housing 18 with an open upper end 20 and a closed lower end22. A drain 23 (FIG. 3) can be located in a threaded opening 24 in thelower end of the housing to allow periodic removal of water from thefilter. Canister has a generally cylindrical shape, although it can beother shapes; and can be formed from material appropriate for theparticular application, such as plastic or metal.

An end cap or lid 28 is attached such as by adhesive, welding or otherbonding means to the upper end of the canister. End cap 28 includes aninlet port or tube 30 with an internal opening 31 to direct fluid to befiltered into the canister; and an outlet port or tube 32 with aninternal opening 33 to direct filtered fluid out of the canister. Afilter element 34 is centrally located in the canister, and has aring-shaped configuration circumscribing a central cavity 35. Element 34includes a lower circular end cap 36 sealingly bonded to the lower endof the media ring, while the upper end of the element is sealinglybonded directly to the end cap 28. Filter element 34 can have astructure (e.g., pleated, fibrous, etc) and be made from a material(e.g., cellulose, polymer) which is appropriate for the particularapplication, and likewise can have a geometry other than ring-shaped ifso desired. While an element is shown and described which cannot beremoved from the canister when spent, or in other words, the entirecanister must be disposed of when the element becomes spent; it is alsoanticipated that the canister could have a removable upper end cap whichwould provide access to the element in the housing to enablereplacement. Such a structure enabling removal of the element (e.g.,threads) should be well-known to those skilled in the art.

In any event, fluid entering inlet port 30 flows into a peripheralannular region 38 between the element and the inside surface of thehousing, where the fluid then flows radially inward through the elementwhere particulate matter and other contaminants are removed, and intothe central cavity 35. If the element has hydrophobic properties, watercollecting on the outer surface of the element can agglomerate, and dripdownward into the lower portion of the housing where it can be removedthrough drain opening 24.

The fluid then flow axially upward and outward through outlet port 32 toreturn to the fluid system. It is also anticipated that the flow throughthe element could be in the reverse direction; that is into port 32 andout of port 30, and travel radially outward through the media.

As indicated above, filter 12 includes structure which enables thefilter to be quickly and easily attached to and removed from bracket 14.To this end, a pair of identical, radially-outward projecting rigidpivots, indicated generally at 40, are provided on the outer surface ofthe canister, on opposite sides thereof, between about the midpoint andthe lower end of the canister. Pivots 40 each comprise a short,axially-extending base 41, and an enlarged circular head 42 projectingradially outwardly toward the lower end of the base. Head 42 includes aflat outer surface 46, and an inwardly-tapered or angled lower surface48 which forms a lip around the head and interconnects the head 42 tothe base 41. Pivots 40 each have a surface extension 50 which isinterconnected to head 42 and is flush (co-planar) with surface 42; thatis, surface extension 50 has the same outer dimension as head 42. Thesides of the surface extension 50 are tapered or angled as at 51, andeach surface extension extends axially a short distance along the sidesurface of the canister toward the open end of the canister from head42. As will be explained below, surface extension 50 of base 41 providesa stand-off against the sidewalls 16 of bracket 14 when the filter ismounted to the bracket.

A series of angled or tapered ridges as at 54 are provided on eitherside of base 41, in axially spaced apart relation and extending in thecircumferential direction, that is, perpendicular to the axial extent ofthe canister, to facilitate locating the filter within bracket 14.Ridges 54 have an outer dimension such that the ridges can engage theinside surface of the sidewalls of the bracket and help direct thefilter between the sidewalls as the filter is mounted to the bracket.One of the ridges 55, has a greater radial projection, in other words,it projects radially outward further than the others, and serves as alocating and supporting ridge for the filter in the bracket, as will bediscussed in greater detail below.

Base 41, head 42 and ridges 54 can all be formed in one piece with thecanister during the forming of the canister; or alternatively can beformed in one or more separate pieces and attached to each other and/orto the canister such as with adhesive or other bonding techniques.

The attachment structure further includes a pair of flexible retainingclips as at 58, also provided on the outer surface of the canister, onopposite sides thereof, between about the midpoint and the upper end ofthe canister. Clips 58 are each in general axial alignment with arespective pivot 40, and can be spaced axially therefrom. Each retainingclip includes a thin, flexible, axially-extending body portion 60, ingenerally parallel relation to the outer surface of the canister, andconnected at a base end 62 to the canister, and extending axially to afree head end 64 spaced radially-outward from the canister. The free end64 of the clips can be flexibly bent toward the canister by appropriatemanual manipulation of the clip. A release tab 66 with a flat outersurface is provided at the head end of the clip to facilitate thismanipulation, and projects generally perpendicular to the extent of thebody portion 60.

A radial projection 68 is provided in generally the middle of each tab66, and extends generally a short distance along the axis of the clip.Radial projection 68 enables the retaining clip to lock to a respectivesidewall of the bracket, and hence retain the filter on the bracket, aswill be described below.

Finally, a radial stand-off 72 is provided in axially-spaced relation toeach tab 66, between the tab and the upper end of the canister, andprojecting radially outward about the same radial distance as tab 66(minus the projection). As will be described below, stand-offs 72prevent sidewalls 16 of bracket 14 from bending clips 60 completelyagainst the surface of the canister, that is, the free ends of the clipsremain somewhat spaced from the outer surface of the canister even afterthe filter is mounted on the bracket, such that the clips can bemanipulated when it is desired to release the filter from its lockedposition with the bracket, as again, will be described more fully below.

Clips 58, tab 66 and standoffs 72 also can all be formed in one piecewith the canister during the forming of the canister; or alternativelycan be formed in one or more separate pieces and attached to each otherand/or to the canister such as with adhesive or other bondingtechniques.

Referring now to FIG. 5, the bracket 14 includes a flat body 79 withapertures 80 or other means to attach the bracket to an appropriatesupport surface, such as an engine block, or engine compartment. Thesidewalls 16 of the bracket are each spaced apart from each other alongopposite sides of body 79, and run generally parallel to each other andperpendicular to the body 79. The spacing of sidewalls 16 is such thatthe filter canister can be generally closely received therebetween.Sidewalls 16 each include a hook-shaped slot, as at 84, along the sideedge of the sidewall and toward the lower end thereof, and openinggenerally toward the upper end of the bracket. The sidewall has atapered or rounded surface 86 around the lower edge of each slot, and atapered or rounded surface 87 around the upper edge of each slot, andthe opening is dimensioned to receive the base 41 of the pivot (FIG. 4)in the area under the head 42.

A thin slot 88 is provided axially upward from opening 84, and extendsfrom the side edge of the sidewall inwardly toward the body 79, that is,horizontally relative to the longitudinal axis of the body. Slot 88provides some flexibility to allow the sidewalls to bend and closelyreceive the filter as the filter is mounted to the bracket. Thesidewalls generally conform as the ridges 54, and in particular locatingridge 55, are received between the sidewall as the filter is pivotedinto its assembled position with the bracket.

An axial slot 90 or other appropriate geometry such as a ridge, is nextprovided axially upward from the slot 88 on the sidewalls toward theupper end of the bracket sidewalls, with slot 90 dimensioned to receivethe projection 68 (FIG. 4) on the tab of the clip. The slot 90 or othergeometry provides a catch which retains the upper end of the filter tothe bracket when the filter is mounted to the bracket, as will bedescribed below.

Finally, each sidewall includes a rounded cut-out shoulder portion 92which is generally dimensioned and located to receive the inlet andoutlet ports 30, 31 (FIG. 1) of the upper end cap when the filter ismounted to the filter head.

During connection of the filter to the bracket, as shown in FIG. 6, thefilter is initially inserted into the bracket such that the pivots 40are each received in a respective slot 84. The slot 84 receives the baseof the pivot, and the filter can pivot around this support while thefilter is being mounted to the bracket, that is, as the filter is beingbrought into axial alignment with and substantially flush against thebody of the bracket. The tapered inner lip surface of each head 42 andthe tapered or rounded lower surface of the corresponding slot 84,facilitates locating the pivots with the slots. As the filter ispivoted, the extended locating ridge 55 on the base of each pivot guidesthe filter between the sidewalls 16. The base projection 50 then engagesthe inside surface of the sidewalls as the tapered sides 51 of theprojection pass inwardly against the rounded upper surface 87 of theslot 84 (in effect pushing the sidewalls outwardly); and, along with thehead 42 being closely received and supported by the rounded edges 86 onthe lower portion of the slot 84 (in effect pulling the sidewallsinwardly), the lower end of the filter is thereby securely held on thebracket when the filter is completely mounted to the bracket (e.g., asshown in FIG. 1).

As the filter is brought into alignment with the bracket, the retainingclips 58 on the filter are received between the sidewalls, andprojections 68 engages the sidewalls, and force the clips slightlyinwardly until the projections pass into the corresponding slots 90 inthe sidewalls. Tabs 66 remain accessible and project outwardly from thesidewalls of the bracket. Stand-offs 72 adjacent the clips keep theupper end of the filter properly centered between the sidewalls andprevent the sidewalls from bending each clip flat against the canister.Once the projections 68 enter their respective slots 90, the clips flexoutwardly and the filter is locked in its horizontal mountingorientation to the bracket. The filter can be supported against the bodyof the bracket, although it can also be held a small distance outwardlytherefrom, as the connection with the pivots 40, including the locatingridges 55, and with the retaining clips 58, securely hold the filter tothe bracket irrespective of whether the filter is supported against thebody. Hoses can then be connected to the inlet port 30 and outlet port32 of the filter to fluidly connect the filter within the fluid system.

To remove the filter from the fluid system, the hoses can be removed,and the tabs 66 of the clips can be accessed and inwardly depressed tomove the projections 68 out of engagement with slots 90, and allow thefilter to be pivoted into the FIG. 6 position, where it can then belifted upwardly and outwardly from the bracket. The pivots 40 aregenerally located on the filter canister such that the filter can bepivoted sufficiently without interference from the end of the canisterbottoming against the bracket or adjacent support surface. Again, thestand-offs 72 of the retaining clips keep the clips at a distance fromthe canister, such that they can be later depressed to allow detachmentof the filter from the bracket.

While the filter has been described above being mounted to a stand-alonebracket, and the bracket is then mounted to an appropriate location suchas to an engine block or engine compartment, it should be appreciatedthat such bracket could be incorporated as an integral part of theengine or compartment, or other support surface. In such case, the bodyof the bracket could be a portion of the engine, engine compartment orother support surface. In addition, while the attachment structure abovehas been described as including the combination of the pivots 40including an enlarged head 42 with lip 48, and extension 50, ridges 54and locating ridge 55; and retaining clips 58 including tabs 66 andprojections 68, it should be appreciated that one or more of thesecomponents on the pivots and/or the retaining clips could be absent onone or both sides of the filter, and the filter 12 could still bemounted to the bracket 14.

Referring now to FIG. 7, after a spent filter 12′ is removed from thesystem, and it is desired to replace the spent filter with a freshfilter 12″, a cap 100 is located on the inlet port 30 of the spentfilter. A short connector tube 102 is then located on the outlet port 32of the spent filter 12′ and connected to the inlet port 30 of the freshfilter 12″. The spent filter 12′ is then inverted as shown, and thedrain 23 in the spent filter (now at its upper end) is opened to allowair to enter the spent filter. As air enters the spent filter 12′, thefluid in the spent filter drains under gravity and passes into the freshfilter 12″. Fluid on the clean side of the spent filter drains directlythrough the outlet port, while fluid on the “dirty” side of the elementdrains through the media and then through the outlet port. The fluidessentially fills the fresh filter and expels the air in the filter outthrough outlet 32 to fully prime the filter. As the volumes of bothfilters are essentially the same, fluid should not pass out of theoutlet port 32 of the fresh filter.

When the spent filter 12′ is completely drained, the connector 102 isremoved from the fresh filter and the fresh filter can be mounted to thebracket as described above. The empty spent filter can then be disposedof in a landfill or other waste disposal facility.

The principles, preferred embodiments and modes of operation of thepresent invention have been described in the foregoing specification.The invention which is intended to be protected herein should not,however, be construed as limited to the particular form described as itis to be regarded as illustrative rather than restrictive. Variationsand changes may be made by those skilled in the art without departingfrom the scope and spirit of the invention as set forth in the appendedclaims.

1. A method for priming a filter, the filter having filtration mediaenclosed within a housing having a drain in a lower end, and the housingincluding inlet and outlet ports in an upper end to direct fluid intoand out of the housing, the filtration media in a fresh filter becomingspent over time as the filter removes particulate and other contaminantsin a fluid stream passing through the media; the method comprising i)closing an inlet port of a spent filter and connecting the outlet portof the spent filter to the inlet port of a fresh filter; ii) invertingthe spent filter; iii) opening the drain in the inverted spent filter toallow fluid in the spent filter to drain under gravity into the freshfilter, and thereby expelling air in the fresh filter through the outletport of the fresh filter; and iv) disconnecting the spent filter fromthe fresh filter.
 2. The method as in claim 1, wherein the spent filteris connected via a tube to the fresh filter.
 3. The method as in claim1, wherein a cap is initially located so as to close the inlet port ofthe spent filter, prior to the spent filter being inverted.
 4. A methodfor priming a filter, the filter having filtration media enclosed withina housing having a drain in a lower end, and the housing including inletand outlet ports in an upper end cap to direct fluid into and out of thehousing, the filter media in a fresh filter becoming spent over time asthe filter removes particulate and other contaminants in a fluid streampassing through the media; the method comprising in sequence: i)locating a cap over the inlet port of a spent filter so as to close theinlet port and connecting the outlet port of the spent filter via a tubeto the inlet port of a fresh filter; ii) inverting the spent filter;iii) opening the drain in the inverted spent filter to allow fluid inthe spent filter to drain under gravity into the fresh filter, andthereby expelling any air in the fresh filter through the outlet port ofthe fresh filter; and iv) disconnecting the spent filter from the freshfilter.